On the thickness distribution and the maximum thinning ratio in hydrostatic forming for sheet metal

2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040144
Author(s):  
Nguyen Thi Thu ◽  
Nguyen Dac Trung

In manufacturing, thickness distribution and maximum thinning greatly affect product quality in sheet metal forming. They depend on many input parameters, such as technological parameters, geometric shape of die, workpiece’s materials and forming methods. Hydrostatic forming technology is particularly suitable for forming thin-shell products with complex shapes. However, due to the forming characteristics, the thinning phenomenon in this technology is much more intense than in other forming methods. Therefore, this study aims to determine the thickness distribution and the relationship between the maximum thinning ratio and input parameters including blank holder pressure, relative depth of the die and relative thickness of the workpiece in this technology. The chosen product shape is cylinder and the chosen method is the orthogonal second-order design. The results are expressed in graphs and functions and they can be applied in product design, calculation and control of input parameters in industrial manufacturing.

2021 ◽  
Vol 15 (1) ◽  
pp. 7824-7836
Author(s):  
Thu Thi Nguyen ◽  
N.D. Trung

In sheet metal forming, thinning phenomenon is one of the most concerned topics to ameliorate the final quality of the manufactured parts. The thinning variations depend on many input parameters, such as technological parameters, geometric shape of die, workpiece’s materials, and forming methods. Hydrostatic forming technology is particularly suitable for forming thin-shell products with complex shapes. However, due to the forming characteristics, the thinning variations in this technology are much more intense than in other forming methods. Therefore, in this paper, an empirical study is developed to determine the thinning variations in hydrostatic forming for cylindrical cup. Measurement of thickness at various locations of deformed products are conducted to investigate the thickness distribution and determine the dependence of the largest thinning ratio on the input parameters (including the blank holder pressure, the relative depth of the die and the relative thickness of the workpiece). The results are expressed in charts and equation which allow determining the effect of each input parameter on the largest thinning ratio.


Author(s):  
O. Ghouati ◽  
H. Lenoir ◽  
J. C. Gelin ◽  
M. Baida

Abstract The paper deals with the design and control of forming processes. The finite element code used is based on isoparametric shell elements with three or four nodes, the workpiece being considered as a sheet metal. An optimization technique is used in order to achieve the design or the control of the process by determining the optimal process parameters. The criterion used in that purpose can be based on thickness distribution as well as the respect of the final shape desired for the product. Numerical examples are presented as illustration.


2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040158
Author(s):  
Nguyen Thi Thu ◽  
Nguyen Dac Trung

Forming fluid pressure is an important technological parameter that determines whether a product can be accurately formed according to the size and profile of the die in hydrostatic forming technology. The expected value of this parameter is often very high because it acts as the punch in forming complex products from sheet metal. However, it is difficult to achieve high values because the forming fluid pressure depends on the ability to hold high pressure of equipment system and input parameters including the blank holder pressure, the depth of die, the thickness of workpiece. Moreover, it is also necessary to have a mathematical model for this parameter to facilitate the calculation and control of the forming process. In order to solve the above problems, this paper will indicate a simple way to avoid the pressure drop during forming process, and establish a regression function relationship between the forming fluid pressure for typical cylindrical product and input parameters above by experimental research method. The results contribute to die design, calculation and control of process parameters to facilitate shaping thin shell products in actual hydrostatic forming technology.


2019 ◽  
pp. 41-48
Author(s):  
Yan Guojun ◽  
Oleksiy Kozlov ◽  
Oleksandr Gerasin ◽  
Galyna Kondratenko

The article renders the special features of the design of a tracked mobile robot (MR) for moving over inclined ferromagnetic surfaces while performing specified technological operations. There is conducted a synthesis of the functional structure and selective technological parameters (such as control coordinates) of the computerized monitoring and control system (CMCS) intended for use with this MR. Application of the CMCS with the proposed functional structure allows substantially increasing the accuracy of the MR monitoring and control, which in turn provides for a considerable enhancement in the quality and economic efficiency of the operations on processing of large ferromagnetic surfaces.


2012 ◽  
Vol 729 ◽  
pp. 169-174 ◽  
Author(s):  
Zoltán Pálmai ◽  
Márton Takács ◽  
Balázs Zsolt Farkas

Having reviewed the literature on cutting and based on the optical, electron-optical and morphological examinations of wear processes we have reached the conclusion that it is possible to describe the abrasive, adhesive and thermally activated diffusion, oxidation processes in a single mathematical model. The model is a non-linear autonomous differential equation, which can be solved by simple numerical methods. The complex wear equation was validated by the results of the cutting tests performed with P20 carbide on C45 carbon steel. If we have this data, we can calculate the activation energy of the process determining the nature of the wear process. The apparent activation energy of wear is Q=151,7kJ/mol. The model can even be used with changing technological parameters, and the data necessary for the constants of the wear equation may as well be determined even by measurements performed on the tool during industrial manufacturing. By the mean of this data, we can calculate the activation energy determining the nature of the wear process.


2013 ◽  
Vol 312 ◽  
pp. 777-781
Author(s):  
Lu Ping Liu

In the modern industrial manufacturing field, PLC plays a very important role. In this paper, through analyzing the working process and control requirements of plate shearing machine and using PLC control technology, the automation design of the plate shearing machine control system is realized.


2006 ◽  
Vol 510-511 ◽  
pp. 330-333
Author(s):  
M.C. Curiel ◽  
Ho Sung Aum ◽  
Joaquín Lira-Olivares

Numerical simulations based on Finite Element Analysis (FEA) are widely used to predict and evaluate the forming parameters before performing the physical processes. In the sheet metal industry, there are basically two types of FE programs: the inverse (one-step) programs and the incremental programs. In the present paper, the forming process of the shield case piece (LTA260W1-L05) was optimized by performing simulations with both types of software. The main analyzed parameter was the blankholding force while the rest of the parameters were kept constant. The criteria used to determine the optimum value was based on the Forming Limit Diagram (FLD), fracture and wrinkling of the material, thickness distribution, and the principal strains obtained. It was found that the holding force during the forming process deeply affects the results, and a range of values was established in which the process is assumed to give a good quality piece.


Author(s):  
Jian An ◽  
A. H. Soni

Abstract The hydroforming technology, which is rapidly gaining popularity in the sheet metal and tube forming industry is reviewed. The features and the characteristics of the hydroforming process are described. The uniformly distributed fluid pressure covers the back side of the sheet as a die generates many advantages in the technical point of view as improving the part surface quality, reducing the forming severity and smoothing the thickness distribution. The benefits of using hydroforming technology are examined and analyzed in a technical level. The better part quality, less cost of tooling, materials saving and part weight reduction can be achieved using the hydroforming technology. The design methodologies for the hydroforming process parameters are reviewed and discussed in a certain detail. Computer-aided-engineering such as finite element simulation is suggested for such process parameter design.


Incremental Sheet metal forming is a die less method of forming which offers high formability. In this research work; effect of step depth, tool rotation speed and preheating temperature on surface roughness and thinning of flange wall is investigated in hole flanging using incremental forming. The parameter optimization is carried out by Taguchi method. Grey relational analysis is carried out to obtain best parameter combination.


2008 ◽  
Vol 575-578 ◽  
pp. 186-191
Author(s):  
Jun Zhao ◽  
Chun Jian Su ◽  
Ying Ping Guan

The main problem in bending process of sheet metal is that it is difficult to control bending springback accurately. Springback produced from the unloading of bending makes the shape and size incongruent between bending workpiece and working portion of die. Because the final shape of bending workpiece is related with the whole deformation process, the geometric parameter of die, material performance parameter will have great effect on springback. Therefore, the springback problem is very complicated and the prediction and control of springback is the key to improve the accuracy of bending workpiece. Taking the V free bending of wide sheet as an object of study, the neural networks technology and data acquisition system based on LabVIEW are used to establish intelligent control experiment system for V free bending of wide sheet metal. The control accuracy of system is high and it provides the basis for the realization of intelligent control for V-shape free bending of wide sheet metal in practice in future.


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